考虑应变强化的高压缩性黏土修正双曲线模型  

Modified Hyperbolic Model of High Compressibility Clay Considering Strain Strengthening Effects

作　　者：程涛[1] 晏克勤[1,2] 

机构地区：[1]黄石理工学院土木建筑工程学院,湖北黄石435003 [2]同济大学土木工程防灾国家重点实验室,上海200092

出　　处：《土木建筑与环境工程》2009年第5期49-53,共5页Journal of Civil,Architectural & Environment Engineering

基　　金：湖北省教育厅优秀青年人才基金项目(Q200830002);黄石理工学院科研基金重点项目(07yjz03R)

摘　　要：研究了武汉地区高压缩性黏土弹塑性本构模型。基于Duncan E～v双曲线模型，对等压固结条件下CTC应力路径三轴实验数据进行了数据拟合，得到了该条件下的非线性应力应变关系，并将卸载-再加载试验曲线的平均斜率作为卸载模量，引入了加卸载函数作为判定加卸载的准则。将该模型嵌入有限元程序对三轴压缩试验进行数值模拟，并与Duncan模型数值解及试验曲线作对比。结果表明，该模型较Duncan模型能更好的体现正常固结黏土在CTC路径下的应力应变关系，特别是加载后期的应变强化效应，与试验曲线的最大相对误差不超过5％。The elasto-plastic constitutive relation of high compressibility clay in Wuhan was investigated. On the basis of the framework of Duncan E-v model, an elasto-plastic constitutive model was derived by fitting the data of triaxial compression tests under CTC stress path on isotropic consolidation condition. With the average slope of unload-reload curves as unload modulus, the loading-unloading function was introduced as the loading-unloading criterion. Moreover, the comparison was made among the stress-strain relation curve simulated by the proposed model and those with Duncan model and test curve. It was shown that the proposed model was more reasonable, which can reflect the stress-strain relation of normally consolidated soils under CTC path. Especially, the model can reflect the strain strengthening effect. The maximum relative error was no more than 5 %.

关 键 词：等压固结 高压缩性黏土 本构关系 非线性 加卸载准则 应变强化 

分 类 号：TU443[建筑科学—岩土工程]